(a)an amount equivalent to decommitments of appropriations, other than external assigned revenue, made cumulatively since 2021, which were not mobilised under this instrument in the previous years, with the exclusion of the amounts of decommitments made available again in accordance with the provisions of Article 15 of the Financial Regulation and specific rules on making appropriations available again as referred to in the relevant basic acts. This amount shall be drawn on first;